MC68HC705JP7CDW Freescale Semiconductor, MC68HC705JP7CDW Datasheet - Page 71

• Manufacturer Part Number: MC68HC705JP7CDW
• Description: IC MCU 8BIT 28-SOIC
• Manufacturer: Freescale Semiconductor
• Series: HC05r

Specifications of MC68HC705JP7CDW

• Core Processor: HC05
• Core Size: 8-Bit
• Speed: 2.1MHz
• Connectivity: SIO
• Peripherals: POR, Temp Sensor, WDT
• Number Of I /o: 22
• Program Memory Size: 6KB (6K x 8)
• Program Memory Type: OTP
• Ram Size: 224 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 4x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Chapter 8
Analog Subsystem
8.1 Introduction
The analog subsystem of the MC68HC705JJ7/MC68HC705P7 is based on two on-chip voltage
comparators and a selectable current charge/discharge function as shown in
This configuration provides several features:
Voltages are resolved by measuring the time it takes an external capacitor to charge up to the level of the
unknown input voltage being measured. The beginning of the A/D conversion time can be started by
several means:
The end of the A/D conversion time can be captured by these means:
Freescale Semiconductor
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Two independent voltage comparators with external access to both inverting and non-inverting
inputs
One voltage comparator can be connected as a single-slope analog-to-digital (A/D) and the other
connected as a single-voltage comparator. The possible single-slope A/D connection provides
these features:
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Output compare from the 16-bit programmable timer
Timer overflow from the 16-bit programmable timer
Direct software control via a register bit
Input capture in the 16-bit programmable timer
Interrupt generated by the comparator output
Software polling of the comparator output using software loop time
A/D conversions can use V
calculate ratiometric or absolute results
Channel access of up to four inputs via multiplexer control with independent multiplexer control
allowing mixed input connections
Access to V
Divide by 2 to extend input voltage range
Each comparator can be inverted to calculate input offsets.
Internal sample and hold capacitor
Direct digital output of comparator 1 to the PB4 pin
MC68HC705JJ7 • MC68HC705JP7 Advance Information Data Sheet, Rev. 4.1
DD
and V
SS
for calibration
DD
or an external voltage as a reference with software used to
Figure
8-1.
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